Tying of knots is essential in any kind of surgery. It is relatively easy in open surgery, but is difficult in laparoscopic surgery. The current art of laparoscopic knot tying employs either the extra-corporeal method, involving tying the knot by hand outside the body and pushing the knot inside with a knot pusher, or the intra-corporeal method, involving manipulation of the suture with the tips of two laparoscopic graspers, which is slow and cumbersome, and requires considerable skill. Laparoscopic clip appliers, staplers, pre-tied knots and the like are useful substitutes, but cannot totally replace tied knots which are still needed. Despite considerable prior art, today hardly any hand operated instrument exists that renders laparoscopic intra-corporeal knot tying easier and faster.
In order to describe the tying process, the different parts of the suture ligature need first be given names. As shown in FIG. 18 in the drawings, after the suture ligature has passed around the tissue to be tied, it then presents with a head end (1), a tail end (2), a leading strand (3) and a tail strand (4),
There are three basic methods of tying a knot, whether done openly or laparoscopically. One method is making a “throw” which involves passing the head end of the suture around its tail strand. This is quite simple as in the tying of shoe laces with fingers. It does however involve a critical step which is the passing or release and re-grab of the head end of the suture, and wrapping it around the tail strand. In laparoscopic surgery this is difficult because the graspers are trapped in the abdominal wall, and the surgeon is limited to using only two laparoscopic graspers, one in each hand.
The second method is making the head end of the suture pass 360 degrees continuously around the tail strand, as is done in the “Automatic Laparoscopic Knot Tying Instrument”, invented by this author, and is noted for avoiding the release and re-grab (see application Ser. No. 14/973,858).
The third method involves making a loop or loops, which is the common practice by surgeons performing open surgery, where the surgeon makes “instrument ties”, by wrapping the leading strand of the suture once or several times around the needle holder, and then pulls the tail end of the suture through the loop or loops. This is impossible with the laparoscopic grasper because the instrument is trapped in the abdominal wall. There have been many different attempts in the prior art trying to make a loop laparoscopically, but none has been effective. The instrument described here is yet another method of making a loop laparoscopically.
In the present invention two small diameter laparoscopic graspers without their handles are incorporated inside a common shaft, with one being stationary and the other extendable and retractable. Two points along the leading strand of the same suture a short distance apart are grasped simultaneously by the jaws of the two graspers. Bringing these two points together forms a loop, with the loop being formed by the portion of the suture between these two points. The tail end of the suture is then brought through the loop by a second instrument in the operator's other hand, thus forming a knot. The operator however must ensure that the loop thus formed is a closed loop, not an open loop. The closed loop is where the loop faces towards the opposing end of the suture, and not away from it. An open loop results where the loop and the opposing end of the suture both face in the same direction.
Referring to the prior art, the most recent is the author's Automatic Laparoscopic Knot Tying Instrument, which uses a mini-grasper at the tip of the instrument grasping the head end of the suture, capable of rotating through 360 degrees around the tail strand, without releasing and re-grabbing the head end of the suture. Included in the prior art is also the author's previous unsuccessful attempt at making a Double Laparoscopic Grasper which was intended to pass the head end of the suture from one grasper to the other across the tail end of the suture. The Christoudias Double Grasper has 3 jaws, with a common middle jaw, but functions as a tissue approximator. Its spring loaded actuators are operated by two push buttons. The Ferzli Double Grasper, has a second pair of jaws positioned more proximally on the main shaft, whose purpose is to anchor one end of the suture prior to twisting it around the shaft of the instrument in order to produce a loop. The Hasson Suture Tying Forceps, is similar to the Ferzli, with 3 finger loops. The orthopedic suture passers are for passing sutures only through hard tissue, and these include the Arthrex Scorpion Suture Passer, and the Arthrex Birdbeak Suture Passer. Some suture passers are for passing sutures through a thickness of soft tissue such as the abdominal wall, and these include the Goretex and the Aesculap. There are devices which “pass the suture-needle” side to side, for inserting sutures into tissues, as well as for tying knots, e.g. the Autosuture's Endo-stitch, and the Japanese Maniceps. Note these only pass the suture needle, not the suture thread per se. There have been devices that attempt to “automatically” tie a knot, such as Jerrigan's experimental rotating slotted disc designed for robotic endo-cardiac surgery, but it was abandoned because of the requirement for a manufactured cartridge.
There have been also many devices that help to “create a loop”, but with each functioning differently—(a) Kitano's grasper with the rotating sleeve, Japanese, (b) Donald Murphy's grasper with the extra horn, Australian, (c) Grice's sleeve catching instrument, (d) Bagnato & Wilson's device which simulates the radiological pig-tail catheter, with a preformed loop built into the tip of the catheter, which is deformable and purportedly a loop former, but it is difficult to manufacture and apply, and has not yet been reduced to practice, (e) Ferzli's double grasper, which anchors one end of the suture, as described above. There have been devices using a “pre-formed knot”, (1) Ethicon's Endo-Loop, (2) the Duraknot, (3) LSI's device, (4) Pare's pre-tied knot, all of which do not help to tie knots.
Past inventions related to intra-corporeal laparoscopic knot tying fail to address the basic problem of “making a loop”. They usually offer various alternatives, such as making fishing knots, using pre-tied knots, knot pushers, suture clips, cinchers, tissue fasteners, anchors, stapling devices, etc. The present invention however will assist in the manual making of a loop in the suture, helping with intra-corporeal knot tying.